Study On The Correlation Between Azole Drugs Cross-resistance And Transcription Factor GCN4 In Candida Albicans

Objective: 1.To explore the drug sensitivity of Candida albicans to fluconazole and verapamil in free and biofilm state.2.To explore the relationship between FCA,ITR and VRC cross-resistance and transcription factor GCN4 in Candida albicans Method:Fifty clinical strains of Candida albicans identified in the Department of Dermatology and Venereology Fungi Laboratory of the Second Hospital of Shanxi Medical University were tested for in vitro drug sensitivity of fluconazole combined with verapamil in free state and biofilm state.MIC50 values of fluconazole combined with verapamil were observed and recorded,and the effects of fluconazole combined with verapamil on free state and biofilm state were explored.In addition,each 10 strains which are susceptible or resistant to fluconazole?Itraconazole and Voriconazole were chosed to build a general and starving Candida albicans model.Then we can extract total RNA,reverse transcription to synthesize cDNA,and detect transcription by Reverse Transcription-Polymerase Chain Reaction(RT-PCR).SO we can try to explore the relationship between the expression of transcription factor GCN4 and azole drugs cross-resistance in Candida albicans.Result: 1.The MIC50 of FCA after combination of fluconazole and verapamil did not conform to normal distribution.Rank sum test was used.The results were expressed by median(quartile spacing).In free state,the median MIC50 values of FCA after combination of fluconazole and verapamil decreased from 16 g/mL to 4 g/mL,z=-4.406,P<0.01,The difference was statistically significant;Verapamil sensitized fluconazole in 20 strains of them,and the sensitization rate was increased 40%.Under biofilm condition,the median MIC50 of FCA decreased from 64 g/mL to 16 g/mL,z =-6.297,P<0.01,The difference was statistically significant;Verapamil sensitized fluconazole in 23 strains of them,the sensitization rate was 46%.2.The mRNA expression level of GCN4 in the sensitive group and the drug-resistant group of Candida albicans was detected.After normality test,the data conformed to be the normal distribution.So the results were expressed as mean ± standard deviation:(1)In the cross-resistant group,the mRNA expression level of GCN4 in starvation status(1.74±0.20)was higher than that in general GCN4(1.14±0.17),P < 0.05,and the difference was statistically significant.(2)In cross-sensitive group: The mRNA expression level of GCN4 in starvation state(1.47±0.15)was higher than that in general GCN4(1.02±0.23),P < 0.05,the difference was statistically significant.(3)Under normal conditions: the mRNA expression level of GCN4 in the Candida albicans resistance group(1.14±0.17)was higher than that in the sensitive group GCN4(1.02±0.23),P>0.05,the difference was not statistically significant.(4)Under starvation status: The mRNA expression level of GCN4 in the Candida albicans drug resistance group(1.74±0.20)was higher than that in the sensitive group GCN4(1.14±0.17),P < 0.05,the difference was statistically significant.Conclusion: 1.The combination of verapamil and fluconazole can increase the sensitivity of fluconazole and provide a new strategy for the treatment of Candida albicans infection.2.The high expression of transcription factor GCN4 in Candida albicans may increase its ability to resist nutritional deficiency and increase its resistance to azole drugs.